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Groundwork & Foundations

When digging out foundations do all sides have to be exactly the same depth and also 90 degrees to the house walls?

Anonymous user 27 October 2011 - 9.18 PM

I have dug foundations out for my conservatory by hand. I have hit sandstone in two trenches but at different depths. It is very hard to dig and therefore the front trench slopes from left to right and the two sides trenches are also uneven. I am best to use my kango to dig the trenches exactly level and the same depth as each other or can I just fill and level off with concrete. The depth of the foundations is in accordance with frost heave considerations and is in fact slightly deeper in places. This is because the soil above the sand stone was still quite soft and I wanted to dig down to a firm base. The variance in depth between the trenches is approx 150 > 200mm. Any advise would be gratefully received.

3 answers from MyBuilder tradespeople

Anonymous user

from ground level to top of the concrete foundation it should be at least 0.450mm to stop frost heave, thats without adding your footing all depends on your levels .take soil out as much as you can BLACK EARTH IS A NO NO ..theres no harm in reinforcing your concrete footing.. but just make sure you stick to the guidelines on the drawings hope this is of a help to you

Answered

27 October 2011

Anonymous user

The depth should usually be around 1 m deep but your building inspector will confirm this as all grounds are different. If you have a tree close to the foundation then it is advisable to dig at least 2 metres due to the roots absorbing water and weakening foundations. Having steps in the foundation are not an issue an is quote common.

Answered

28 October 2011

Anonymous user

If this is being done to building regs, get the building inspector out to check the trenches prior to pouring concrete. If you have hit good solid ground you should be ok, it doesnt matter to much if you have steps in the ground works, so long as you get the concrete level for building of.

Answered

27 October 2011